The best solar panel companies are the ones that design a system around your home, explain its likely performance clearly and remain accountable after installation. A low quote can be poor value if it assumes an unsuitable system size, overlooks roof work or leaves you to coordinate approvals and repairs. Compare proposals on equal terms: equipment, expected generation, installation scope, warranties, financing and ongoing support. For New Zealand homeowners, also ask how the installer will handle the connection with your local electricity network and what assumptions it makes about power exported to the grid. The right choice depends on your roof, electricity use and plans for the property.
The phrase can refer to a panel manufacturer, a retailer, an installation company or a business that sells a package and subcontracts the work. These roles are not interchangeable. A manufacturer makes equipment; the company quoting your project may be responsible for system design, installation, electrical work, network paperwork and service if something goes wrong.
Start by identifying who will do each part of the job. If a salesperson or broker is arranging the installation, ask which business will appear on the contract and which will handle faults. A well-known panel brand does not, by itself, establish the quality of the installer or the support you will receive.
There is no single company that is best for every home. A household that uses most of its electricity during daylight may value a different system from one with high evening use, plans to add an electric vehicle, or wants battery backup. The strongest proposal is the one that fits your circumstances and makes its assumptions easy to check.
Before judging the total price, make sure each company has quoted for a comparable system. A proposal for a larger array or different inverter setup cannot be compared fairly with a smaller or differently specified package. Ask each company to state the system’s capacity, the main equipment models, the expected annual generation and exactly what installation work is included.
| What to compare | What a useful proposal explains | Question to ask |
|---|---|---|
| System design | Panel layout, capacity, roof suitability and generation assumptions | How did you account for roof orientation, shade and my electricity use? |
| Equipment | Panel, inverter and battery models, if included | Why do these components suit this roof and system size? |
| Installation | Labour, electrical work, mounting, commissioning and exclusions | Who will do the work, and what is not included in the quote? |
| Warranties and service | Separate equipment and workmanship coverage, plus the claims process | Who pays for diagnosis, labour or equipment removal if a fault occurs? |
| Financial case | Upfront cost, finance terms and savings assumptions | What happens to the estimate if export payments or electricity prices change? |
Look closely at the generation estimate. It should be based on your roof’s layout and shading rather than a generic figure for a typical house. Ask what assumptions were used and whether the estimate distinguishes electricity you expect to use at home from electricity exported to the grid. The distinction matters because the value of exported power depends on the terms offered by your electricity retailer and may differ from the value of using solar electricity yourself.
Ask how the proposed system size relates to your actual consumption. Recent power bills can help a designer understand your usage, but a single annual total does not show when electricity is used. If you can, review your consumption patterns through your retailer or meter data. A system sized only to maximise panel capacity may not be the best fit if much of its output would be exported at a rate that does not suit your financial assumptions.
A reputable installer should assess the roof’s usable area, orientation, shading and condition. Ask whether the site assessment was done in person or remotely, and what would trigger a revised design after a closer inspection. Trees, nearby buildings, roof features and the arrangement of panels can all affect expected output.
Roof age deserves particular attention. If the roof may need repairs or replacement soon, discuss that before installation. Removing and reinstalling a solar array later can add work and expense, so it may be sensible to complete roof work first. Ask how the mounting system will be fixed to the roof, how penetrations will be managed and whether the proposed work affects any existing roof warranty.
Do not accept a system diagram that is too vague to review. The proposal should show where panels will go and identify the equipment being supplied. If a company recommends a larger or smaller system than another bidder, ask it to explain the difference in terms of your roof, current use and likely future needs—not just the maximum number of panels that can fit.
Solar panels are only one part of the installation. The inverter converts the panels’ output into electricity that can be used in the home or exported. Ask whether the proposal uses a string inverter, microinverters or another configuration, and why that arrangement suits the roof. Different designs can respond differently to roof layout and shading; the best choice depends on the site and the equipment being offered.
Compare exact model names, not just broad labels such as “premium” or “high efficiency.” Ask whether the quoted components are available as specified, whether substitutions are allowed and how you will be told if a model changes. A company should be able to explain its equipment selection in plain language without suggesting that one brand automatically guarantees better installation or savings.
A battery may be useful if your priorities include using more of your solar generation later in the day or having backup for selected circuits. It is not automatically a good financial choice. Ask for the battery’s usable capacity, what the system can power during an outage, and whether backup requires additional equipment or wiring. Some grid-connected systems do not provide household power during a grid outage unless designed for that purpose.
Request a separate estimate with and without a battery. That makes it easier to see what the storage equipment adds to the upfront cost and the projected bill savings. Check whether the estimate assumes the battery will charge from solar, the grid or both, and whether it accounts for how often the household is likely to use stored energy.
Solar equipment often comes with manufacturer warranties, but those are not the same as the installer’s workmanship coverage. Ask for the warranty documents and identify who is responsible for each type of claim. A panel warranty may not cover the labour required to diagnose a problem or remove equipment, and an installer’s business arrangements may affect how easy it is to obtain service later.
Get clear answers to these questions:
Ask the company how it handles service requests and whether it maintains a local team or uses subcontractors. Subcontracting is not automatically a problem, but you should know who is accountable for the work and how a problem will be resolved. For electrical work in New Zealand, ask who will carry it out and how you can verify the relevant worker’s registration with the Electrical Workers Registration Board.
Quotes can differ because they include different amounts of work. Check whether the price covers mounting equipment, wiring, electrical protection, commissioning, monitoring setup, removal of old equipment if relevant, and any required network application or coordination. Ask the installer to list exclusions in writing, including any work that might be needed if the roof or electrical setup differs from what the initial assessment found.
A grid-connected solar system may need approval or coordination with the local electricity distribution network before it can export power. The process and technical requirements can depend on the network serving the property. Ask the company whether it handles this process, what information it needs from you and whether the quoted design could change to meet network requirements.
Also confirm the arrangements with your electricity retailer. Export payments and plan terms vary, so do not treat a projected buyback amount as guaranteed for the life of the system. Ask which retailer and export assumptions were used in the savings estimate, and rerun the numbers if you expect to change retailers or plans.
Compare the total cost of each offer, not just the monthly payment. For a financed system, request the interest rate, fees, repayment period, total amount payable and any conditions for early repayment. Confirm who owns the equipment during the agreement and whether the finance arrangement affects a future home sale or refinancing.
Be cautious with savings projections that rely on electricity prices rising, generous export payments continuing or a battery eliminating most bills. Ask for the assumptions in writing and request a conservative scenario as well as the company’s main estimate. A useful projection should show how the system’s expected generation, household use, exported electricity and applicable charges contribute to the result.
If a proposal uses a lease or power-purchase arrangement rather than a straightforward purchase, read the contract carefully. Check the agreement’s term, payment changes, maintenance responsibilities, end-of-contract options and what happens if you sell the home. These arrangements may suit some households, but the lower initial outlay should be weighed against ownership, flexibility and the full amount payable.
Pause if a salesperson pressures you to sign immediately, promises a fixed level of savings without showing the assumptions, or cannot identify the equipment being offered. A quote that omits roof assessment, installation exclusions or warranty responsibility is difficult to compare and may leave important costs unresolved.
Be wary of a company that treats a battery as essential without asking about your usage or backup priorities. The same caution applies to a proposal that relies heavily on exported electricity income without naming the retailer assumptions. Ask for a revised explanation, and do not proceed until you understand what you are buying and who is responsible for the work.
Not without checking that the proposals cover the same system, equipment and installation scope. A lower price may be good value, but it could also reflect a smaller array, different components or excluded work. Compare the written specifications and total costs before deciding.
Usually, the company selling or installing a home system is not the panel manufacturer. Evaluate the installer’s design, workmanship, accountability and support separately from the equipment brand. Ask who handles a warranty claim if the manufacturer and installer are different businesses.
No. A battery can help shift some solar electricity to later use or provide backup when the system is designed for it, but it adds cost and may not suit every household. Compare the system economics and backup features with and without storage.
There is no fixed number that suits every project. Comparing proposals from more than one installer can help you spot differences in design, scope and assumptions, provided you give each company the same information and compare like with like.
Confirm the equipment models, system layout, total price, exclusions, warranty responsibilities, financing terms and process for network coordination. Make sure any promised changes or conditions are written into the contract rather than left as verbal assurances.
The best solar panel companies make it possible to understand what will be installed, how the design suits your home and what the financial estimate depends on. Compare the full proposal, verify who will do the work and ask for unclear assumptions to be corrected before you commit. A system that matches your roof, electricity use and long-term plans is a stronger choice than a low quote that leaves those details unanswered.
